Numerous investigations have been published in the scientific literature relating to the synthesis of spiranic lactones. One can revert to the articles of J. Moulines and R. Lalande in Comptes Rend. 261, 1983 (1965) and in Bull. Soc. Chim. France 1075-1080 (1971), or to one of the following papers:
G. I. Nikishin et V. D. Vorob'ev, Isvestiya Akademii Nauk SSSR, Otdelenie Khimicheskikh Nauk 10 (1962) 1874-76; PA0 P. Canonne et al., J. Org. Chem., 46, 3091-7 (1981); PA0 S. Tatsuya et al., Tetrahedron Lett. 21, 5029-32 (1980); PA0 R. M. Jacobson et J. W. Clader, Tetrahedron Lett. 21, 1205-8 (1980); PA0 P. Canonne et al., J. Org. Chem. 45, 1828-35 (1980).
Japanese Patent Application No. 55/76843, published on June 10, 1980, discloses a process for the preparation of cycloaliphatic esters starting from spiranic lactone (I). This application however is mute as to the fragrance characters of the lactone starting material and no suggestion has been made therein to its possible use in the area of perfumery.
European Patent Application published under No. 105157 Apr. 11, 1984 describes a series of spiranic lactones of general formula ##STR3## wherein R designates a C.sub.1-4 alkyl radical, and their utilization as perfume ingredients. The said European application does not mention, nor suggest the possibility of employing lactone (I) in the same area of use.
The table given hereinbelow enumerates the compounds defined by general formula (II) and summarizes their fragrance properties as described in above cited European Patent Application No. 105157.
______________________________________ R Odour ______________________________________ CH.sub.3 powerful, creamy, lactonic, coumarin direction, weakly cresylic C.sub.2 H.sub.5 strong, creamy, lactonic, slightly woody iso-C.sub.3 H.sub.7 woody, milk-lactonic type, powdery sec-C.sub.4 H.sub.9 peach direction, apricot, lactonic tert-C.sub.4 H.sub.9 woody, ambery, weak ______________________________________
8-Isopropyl-1-oxaspiro[4.5]decan-2-one and 8-ethyl-1-oxaspiro[4.5]decan-2-one were identified by applicant as being the preferred compounds.